The objective of the proposed research is definition of the relationship among zinc depletion, chronic alcoholism, and disturbances in intestinal and hepatic folate metabolism. The intestinal absorption of folates will be measured by jejunal perfusion in cirrhotic and non-cirrhotic chronic alcoholic patients and the results correlated with measurements of plasma zinc and urinary zinc excretion. A rat model will be used to measure the effect of dietary zinc depletion, with and without the chronic administration of ethanol, upon the activities of intestinal folate conjugase upon folate absorption from perfused in vivo loops, and upon the hepatic uptake and metabolism of tracer dose of labeled folic acid. The zinc requirement of intestinal folate conjugase will be studied by measurement of activities in presence and absence of zinc and by quantitation in the purified enzyme.